Biomedical subjects

Y Ichikawa

Publications and source records attributed to Y Ichikawa.

At least 955 records · Page 53Linked to original sources

PubMedDate not supplied

A new antithrombogenic RV-PA valved conduit.

A new antithrombogenic right ventricular (RV)-pulmonary artery (PA) valved conduit was developed using a bovine jugular vein containing a natural valve. To maintain the natural and mechanical properties of the venous tissue, a hydrophilic cross-linking reagent, glycerol polyglycidyl ether polyepoxy compound (PC) was used instead of glutaraldehyde (GA). Moreover, to induce antithrombogenicity, heparin was bonded to the inner surface of the bovine jugular vein cross-linked with PC. Conduits of 18 to 20 mm inner diameter (ID) were implanted between the RV and PA in nine dogs weighing 7-17 kg, with the native main PA being ligated proximally. The handling and suturing of the graft was easy and adaptable, and the anastomosis was completed with excellent coaptation and no blood leakage at the suture lines. All animals were chronic survivors, but one animal died of hematemesis on the 438th postoperative day. Grafts were explanted from 182 to 385 days after implantation. The luminal surface of the conduits were white, glistening, and smooth with good coaptation of the cusps, without calcification or degenerative changes except for one cusp that showed a minimal deformation with a small thrombus. Macroscopic and microscopic observation showed that there were no thrombi at the anastomotic lines, but small thrombi on the luminal surface of the conduits near the cusps and in some cusps. Endothelium-like cells were noticed on the luminal surface of the graft, except in the area near the cusps, and on one cusp at 196 days after surgery. These results indicated that the new RV-PA valved conduit provided adequate antithrombogenicity by temporary slow heparin release, followed later by endothelialization of the graft in a low pressure system at 1 year after implantation.

Animals↗

PubMedDate not supplied

Measurement of cytokine levels by coronary sinus blood sampling during cardiac surgery with cardiopulmonary bypass.

Interleukin-6, interleukin-8, and polymorphonuclear leukocyte elastase levels in coronary sinus blood were measured and compared with those in arterial blood drawn from the radial artery before and immediately after cardiopulmonary bypass (CPB) during coronary artery bypass grafting in 20 patients. We introduced coronary sinus blood sampling as a useful method for evaluation of myocardial metabolism, myocardial protection, and reperfusion injury during CPB, especially by measurement of cytokines. Because interleukin-6, interleukin-8, and polymorphonuclear leukocyte elastase are inflammatory mediators, we speculated that they might show higher levels in coronary sinus blood than in systemic arterial blood. The results obtained from the 20 patients showed that levels of interleukin-6, interleukin-8, and polymorphonuclear leukocyte elastase increased immediately after CPB (p < .01), but there was no significant difference in these levels between coronary sinus and systemic arterial blood. We conclude that the myocardium is not a predominant source of their release during CPB. Our results also showed that the measurement of these cytokines in systemic arterial blood reflected their levels in the whole body, including the myocardium, even during cardiac operation with CPB.

Adult↗

PubMedDate not supplied

Lung cyst formation in lymphocytic interstitial pneumonia: CT features.

OBJECTIVE: We performed this study to identify and characterize the CT findings of lymphocytic interstitial pneumonia (LIP). MATERIALS AND METHODS: The CT findings of two patients with LIP were reviewed and correlated with their histologic specimens. RESULTS: Chest CT of the two patients showed areas of increased attenuation in both lung fields which were associated with nodular and cystic lesions surrounding the peribronchovascular bundles. The most characteristic abnormality identified on CT was the presence of multiple cysts throughout both lungs. Macroscopic findings of lung biopsy specimens included multiple nodular and cystic lesions. CONCLUSION: This description of multiple pulmonary cysts formation in LIP is new.

Adult↗

PubMedDate not supplied

Effects of arachidonic acid metabolites and interleukin-1 on platelet activating factor production by hepatic sinusoidal endothelial cells from mice.

The effects of interleukin-1 (IL-1) and arachidonic acid metabolites, prostaglandin (PG) E1, leukotriene (LT) B4 and LTC4, on the amount of platelet activating factor (PAF) produced and released by mouse hepatic sinusoidal endothelial cells were investigated. When hepatic sinusoidal endothelial cells were incubated with 1 microgram/mL of calcium ionophore (CaI) A23187, PAF production increased until 20 min after the start of incubation, but when the cells were incubated with PGE1 and CaI A23187, PAF production was significantly suppressed. On the other hand, when hepatic sinusoidal endothelial cells were incubated with IL-1 beta, LTB4 or LTC4 alone, PAF production significantly increased compared with that of the cells incubated without these substances. However, when the cells were incubated with PGE1 alone or with IL-1 beta, LTB4 or LTC4 and CaI A23187, these effects were not observed. These results indicated that PAF produced by hepatic sinusoidal endothelial cells is affected by IL-1 and arachidonic acid metabolites, suggesting that immune and inflammatory reactions in these cells may be regulated by chemical mediators produced by the cells themselves.

Alprostadil↗

PubMedDate not supplied

Factor V deficiency in a patient with rheumatoid arthritis.

Factor V deficiency associated with rheumatoid arthritis was found in a 54-year-old woman. Hereditary factor V deficiency is very rare; only about 150 cases have been reported since its discovery in 1943. This appears to be the first case report of factor V deficiency associated with rheumatoid arthritis in the literature.

Arthritis, Rheumatoid↗

PubMedDate not supplied

The elevated mRNA content as a potential indicator of precancerous states of the gallbladder mucosa in patients with pancreaticobiliary maljunction.

Pancreaticobiliary maljunction (PBM) patients have a high incidence of cancer in the gallbladder. In the present study, we showed that precancerous lesions in the gallbladder of PBM such as hyperplasia or metaplasia, indicated high concentration of the amount of total mRNA. The mRNA content could be easily measured by our new technique utilizing a GenePlate, which is a poly (dT) oligonucleotide immobilized plastic plate, and Yoyo-1, a fluorescent DNA intercalator. To standardize the mRNA contents, we utilized which was defined as the ratio of total mRNA contents to total nucleic acids in a same sample. The mRNA index of the proliferating cells was significantly higher than that of the resting cells, and the mRNA index of cancer cells, such as gastric cancer, colon cancer, bile duct cancer, and gallbladder cancer also showed significantly higher concentration than that of normal mucosa. In the study of precancerous lesion, PBM, the mRNA index was significantly higher than that of mild cholecystitis but less than that of gallbladder cancer, suggesting that in the gallbladder mucosa of PBM, a precancerous state was able to be diagnosed by the mRNA index.

Animals↗

PubMedDate not supplied

Serotyping of dengue viruses by an enzyme-linked immunosorbent assay.

We have developed a sandwich enzyme-linked immunosorbent assay for serotyping dengue viruses. In this assay, we used antibody from dengue hemorrhagic fever patients for detection of flavivirus common antigens to confirm virus isolation in C6/36 cells and that from hyperimmune mouse ascitic fluids for serotyping. The anti-dengue antibody was immobilized on microplate wells for capturing of dengue antigens, which were then sandwiched with the same biotinylated antibody. Then the biotin in the solid phase was detected with peroxidase-conjugated streptavidin. We found that all the dengue strains tested were unequivocally identified by this method.

Antibodies, Viral↗

PubMedDate not supplied

Sialyl Lewis X expression in vascular permeating lesions as a factor for predicting colorectal cancer metastasis.

BACKGROUND/AIMS: To evaluate the potential of sialyl Lewis X (SLX) expression for predicting residual liver recurrence, we examined the vascular permeating lesions surrounding the metastatic liver tumors for SLX as a marker of residual liver recurrence. METHODOLOGY: Twenty-eight cases of metastatic liver tumors of colorectal cancers were examined using SLX monoclonal antibody for SLX expression in surrounding vascular permeating lesions. RESULTS: The cumulative residual liver recurrence rate in cases positive for SLX (SLX(+)) expression in the vascular permeating lesions surrounding the metastatic liver tumor was significantly higher than in the negative cases (p < 0.05). Furthermore, logistic regression analysis revealed that SLX positivity in the lesions surrounding the metastatic liver tumor was an important discriminant for residual liver recurrence (p = 0.0197). CONCLUSIONS: These results indicated that SLX expression in vascular permeating lesions surrounding the metastatic liver tumor is a predictive factor for residual liver recurrence.

Biomarkers, Tumor↗

PubMedDate not supplied

Correlation of immunohistochemical p53 labeling index with inhibition rate in chemosensitivity test in gastric and colon cancer.

To determine whether the expression of p53, p21, bcl-2 or Ki-67 in cancer cells is predictive of chemosensitivity, immunohistochemical examination of these factors and chemosensitivity assays were performed on colon and gastric cancer specimens. Chemosensitivity tests were performed using CDDP, 5-FU, MMC, or ADR and inhibition rate (IR) was calculated by MTT assay. Before exposure to anticancer drugs, the samples were investigated immunohistochemically for expression of the above factors and after anticancer drug exposure by TUNNEL staining, for the presence of apoptotic cells. With 5-FU and MMC, the apoptotic index was well correlated with IR, so their effects were related to apoptosis. Moreover, with these two agents, the p53 labeling index (LI) was inversely correlated with IR and p21-LI showed a good correlation with IR. We therefore concluded that immunohistochemical studies for p53 and p21 were useful for predicting the chemosensitivities of colon and gastric cancer to MMC and 5-FU.

Antineoplastic Agents↗

PubMedDate not supplied

Accessory molecules expressed on the peripheral blood or synovial fluid T lymphocytes from patients with Sjögren's syndrome or rheumatoid arthritis.

We previously demonstrated that the cells expressed by activation antigens were increased in several T cell subsets from the peripheral blood (PB) and joint fluid (JF) of patients with Sjögren's syndrome (SS) or rheumatoid arthritis (RA). In the present report, we further determined by three-color flow cytometry the homing receptors (Leu8) for peripheral lymph nodes expressed on naive (CD45RA+) or memory (CD45RA-) CD4+ cells and on the two subsets of CD8+ cells (CD11b+ and CD11b-) in the PB and JF from SS and RA patients. In addition, the activation antigens (HLA-DR) and two adhesion molecules, including the alpha-chain of the leukocyte function associated antigen-1 (LFA 1 alpha: CD11a) and its ligand (intercellular adhesion molecule-1: ICAM-1: CD54) expressed on T cells, were compared. We found that CD45RA-CD4+ cells were markedly increased in JF, while CD45RA+CD4+ cells were almost absent. Leu8+ cells were decreased in both CD45RA-CD4+ and CD8+CD11b-cells (cytotoxic T cells) in the JF, and were also decreased in the CD8+CD11b-subset in the patients' PB. Furthermore, activated (DR+) T cells were markedly increased in JF, and the cells expressed more adhesion molecules in both the PB and JF from patients, compared with the DR-T cells. The DR+ T cells therefore are considered to be memory T cells, which are more efficient for cell-to-cell interactions. These observations also suggest that the Leu8- and DR+ T cells with increased adhesion molecules might preferentially migrate into inflammatory tissues, and that naive T cells are being further converted to to memory T cells by in vivo stimulation within the tissues.

Adult↗

PubMedDate not supplied

Clinical significance of serum CEA protein and CEA mRNA after resection of colorectal liver metastases.

BACKGROUND: It is difficult to predict the recurrence of colorectal liver metastasis after curative hepatectomy. We investigated the relationship between subsequent metastasis and both CEA protein and CEA mRNA (TaqMan PCR) diachronic levels. PATIENTS AND METHODS: The subjects were 30 patients with colorectal liver metastases. Serum CEA protein and CEA mRNA assays were performed every month after hepatectomy. RESULTS: Metastasis recurred in 21 of the 30 patients. The CEA mRNA assay showed 26 cases with high (H) levels and 4 with low (L). Among the 15 patients whose protein levels were not elevated (NE group), 6 had recurrence; all 6 belonged to the mRNA H group. None of the 4 patients in the mRNA L group had recurrence. In the protein-elevated (E) group (DFI > 6 months) (n = 7), mRNA was elevated in 5 cases (71.4%) 6 months before recurrence, whereas protein was elevated in 1 case. The sensitivity, specificity and accuracy of CEA protein/mRNA for identifying recurrence were 71.4/100, 100/44.4, and 80/83.3%, respectively. CONCLUSION: CEA mRNA is more sensitive than CEA protein in detecting recurrence. CEA mRNA may be useful for identifying high-risk groups or detecting recurrence at an early stage, when the CEA protein level is still low.

Aged↗

PubMedDate not supplied

Association of enhanced superoxide generation by neutrophils with low superoxide scavenging activity of the peripheral blood, joint fluid, and their leukocyte components in rheumatoid arthritis: effects of slow-acting anti-rheumatic drugs and disease activity.

To study the role of the superoxide radical (O2-) in the pathogenesis of rheumatoid arthritis (RA), both the O2- generation of peripheral blood (PB) polymorphonuclear cells (PMN) and the superoxide scavenging activity (SSA) of PB-PMN, plasma, joint fluid (JF) and PB- or JF-mononuclear cells (MNC) were measured in forty-five patients with RA using the highly sensitive and specific 2-methyl-6-methoxyphenyl-3,7-dihydroimidazo[1,2-alpha] pyrazin-3-one dependent chemiluminescence and the electron paramagnetic resonance/spin trapping methods, respectively. Since many drugs, particularly the slow-acting anti-rheumatic drugs (SARDs) used in RA, may alter O2- metabolism, the effects of SARDs on SSA were also studied. The basal O2- release and opsonized zymosan- or phorbol myristate acetate-stimulated O2- generation by PB-PMN from RA patients were significantly increased, while the SSA of PMN was decreased as compared to those from healthy controls. In addition, the SSA of PMN showed a negative correlation with their O2- generation rates. The JF-PMN showed lower SSA levels than PB-PMN. A negative correlation was also found between the SSA of the plasma and the erythrocyte sedimentation rates. The SSA of the plasma, PB-PMN, JF and JF-PMN were significantly higher in patients treated with SARDs than those without. In cell-free systems, sulfasalazine (SAP) and its metabolite, 5-amino-salicylic acid, had a direct SSA within a millimolar range. The other metabolites of SASP and D-penicillamine had an indirect SSA, since they affected the O2- generating system. Auranofin and bucillamine had no SSA. However, none of the SARDs examined could scavenge O2- at concentrations reported in patients' plasma.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMedDate not supplied

Enhanced superoxide generation and the decreased superoxide scavenging activity of peripheral blood leukocytes in Behçet's disease--effects of colchicine.

Enhanced superoxide radical (O2-) generation by polymorphonuclear cells (PMN) has been suggested to mediate tissue damage associated with Behçet's disease (BD). Because superoxide dismutase (SOD) provides protection from O2- we investigated whether the superoxide scavenging activity (SSA) of PMN, mononuclear cells (MNC) or plasma has a correlation to the amount of O2- generated by PMN in BD. We also studied the effects of colchicine, a potent inhibitor of phagocytosis, on the SSA of PMN. In BD, O2- release by both non-stimulated PMN and those stimulated with opsonized zymosan (OZ), or 4 beta-phorbol 12 beta-myristate 13 alpha-acetate (PMA), was enhanced. The SSA of PMN, but not MNC and plasma, was significantly lower in BD patients as compared with healthy controls. The SSA of PMN showed a strong negative correlation with their O2- release. The SSA of PMN was lower in the BD patients with elevated erythrocyte sedimentation rates and C-reactive protein levels than in those with normal test results. In addition, we found that colchicine treatment increased the SSA of PMN toward normal levels in BD patients. In vitro studies demonstrated that the SSA in PMN obtained from healthy adults was decreased after stimulation with either OZ or PMA. Colchicine could prevent the decrease in the SSA when PMN were stimulated with OZ, but not when stimulated with PMA. Our results suggest that the enhanced O2- release by PMN in vivo may be responsible for the decreased SSA of PMN in BD and the PMN might be able to release more O2- in tissues. Colchicine may increase the SSA of PMN toward normal levels by blocking phagocytosis.

Adult↗

PubMedDate not supplied

Serum thrombomodulin and anticardiolipin antibodies in patients with systemic lupus erythematosus.

Since thrombomodulin (TM) is a specific cell surface glycoprotein for vascular endothelial cells, serum TM (s-TM) might be a useful marker of endothelial cell damage. Antiphospholipid antibodies (aPL) frequently detected in systemic lupus erythematosus (SLE) have been associated with vascular occlusive diseases. Therefore we measured the s-TM in 60 patients with SLE, in 23 patients with other diseases including aPL (disease control group) and in 26 healthy subjects, by means of an enzyme immunoassay using monoclonal antibodies to human TM. A significant positive correlation was found between s-TM and serum creatinine levels in SLE patients (r = 0.813, p less than 0.001). When the s-TM level was divided by the serum creatinine level (TM/Cr) to exclude the effect of renal clearance, the TM/Cr ratios were significantly increased in SLE patients with active lupus nephritis (LN) compared to those without LN (p less than 0.05). The ratios did not correlate with the presence of aPL or antiphospholipid antibody syndrome (APLS) in SLE patients or in the disease control group, although a weak correlation between the TM/Cr ratios and IgG-anticardiolipin antibody titers was found in the SLE patients without LN (r = 0.449, p less than 0.01). The present results suggest that elevated TM/Cr ratios reflect renal and possibly extra-renal endothelial cell damage in SLE patients with active LN, but that s-TM levels do not associate with the presence of aPL or a history of APLS.

Adult↗

PubMedDate not supplied

Colonic J-pouch decreases bowel frequency by improving the evacuation ratio.

BACKGROUND/AIMS: To compare the functional outcome of ultra-low anterior resection for rectal cancer with colonic J-pouch reconstruction with that of straight reconstruction. METHODOLOGY: Twenty-three patients who underwent ultra-low anterior resection with or without J-pouch reconstruction underwent bowel transit study, videodefecography, and answered a questionnaire survey 4 months and 1 year after surgery. Eleven healthy subjects underwent similar testing as controls. RESULTS: Patients with a J-pouch had less frequent stools than patients with straight reconstruction 4 months after surgery (p<0.05), but the two groups were similar at 1 year. Bowel transit time was similar at both study points. The evacuation ratio was higher after J-pouch than straight reconstruction 4 months after surgery (p<0.05). However, the ratio improved in the straight group, and no difference existed at 1 year. Colonic contraction was seen only near the anastomosis 4 months after surgery, but the contraction proximal to the anastomosis improved over the next 8 months. CONCLUSIONS: J-pouch reconstruction facilitates evacuation by improving the evacuation ratio. Although straight anastomosis caused excessive stool frequency 4 months after surgery, colonic function continued to improve and was comparable with J-pouch and straight reconstruction 1 year after surgery because the contraction ratio proximal to the anastomosis improved.

Aged↗

PubMedDate not supplied

T cells bearing gamma/delta T cell receptor and their expression of activation antigen in peripheral blood from patients with Sjögren's syndrome.

T cells bearing gamma/delta T cell receptor (gamma/delta + T cells) and their expression of activation antigen (HLA-DR) or the marker of natural killer (NK) cells (CD56), were examined in the peripheral blood lymphocytes (PBL) from twenty-two patients with Sjögren's syndrome (SS) by three-color flowcytometry to elucidate possible pathological roles of the T cell subset in SS. The frequency of gamma/delta + T cells in PBL was not elevated in SS patients, while that of gamma/delta - T cells, which are T cells bearing the alpha/beta T cell receptor (alpha/beta + T cells), was significantly low in the patients, as compared with 22 healthy controls. We found that the proportions of activated cells (HLA-DR+) in both the gamma/delta + and alpha/beta+T cell subsets were significantly higher in the patients than in the controls. The proportions of HLA-DR+ cells in cells in both patients and controls. Furthermore, the frequency of activated cells in both T cell subsets correlated with the duration of disease in SS patients. However, no difference was found in the percentages of total CD56+ cells, CD56+CD3- cells (true NK cells), CD56+CD3+T cells, CD56+gamma/delta+T cells, or CD56-gamma/delta+T cells between the patients and controls. The above results indicate that immunologic activation in SS patients is progressive and involves both alpha/beta+ and gamma/delta+ T cell subsets.

Adult↗

PubMedDate not supplied

Activation antigens expressed on T-cells of the peripheral blood in Sjögren's syndrome and rheumatoid arthritis.

We analyzed activated T-cells in the peripheral blood (PB) of 29 patients with Sjögren's syndrome (SS: 13 I degrees-SS and 16 II degrees-SS patients) and 11 patients with rheumatoid arthritis (RA) by two-color flowcytometry using antibodies to antigens serially expressed on the cell surface after activation--interleukin-2 receptor (IL-2R), HLA-DR, T-lineage specific antigen (TLiSA-1) and very late antigen (VLA-1). The early and intermediate activation antigens, DR and TLiSA-1, were significantly increased in the PB of SS and/or RA patients. The proportions of activated T-cells were higher in CD8+ cells than those in CD4+ cells. T-cells expressing IL-2R or VLA-1, which appear in the very early or late stages of activation, were also increased in SS and/or RA patients. The results suggest that activated T-cells in the PB of both diseases might be recruited from continuously activated lymphoid organs, and that the activated cells migrate from PB into target tissues. In addition, the increase of activated T-cells in PB might be one of the causes of the deficient cell-mediated immunity reported in these patients.

Adult↗

PubMedDate not supplied

Reactivities of antiphospholipid antibodies to blood cells and their effects on platelet aggregations in vitro.

To clarify the pathogenesis of antiphospholipid antibody (aPL) syndrome, the reactivities of anticardiolipin antibodies (aCL) in sera of patients with systemic lupus erythematosus (SLE) or other diseases to fresh, activated or destroyed blood cells were examined by the inhibition assay using an enzyme-linked immunosorbent assay. In addition, the effects of lupus anticoagulants (LA) in the patients' plasma and of immune complexes formed between LA and PL antigens on platelet aggregations were also determined. The IgG-aCL activity of patients' sera was markedly inhibited by pre-incubation with freeze-thawed blood cells, including erythrocytes (RBC), mononuclear cells (MNC) and platelets, but not fresh platelets or RBC. The aCL activity was slightly inhibited by fresh MNC, and was definitely inhibited by thrombin-activated platelets and polymorphonuclear cells (PMN) stimulated with phorbol 12-myristate 13-acetate (PMA). However, the activity was not inhibited by platelets stimulated with adenosine 5'-diphosphate (ADP; 10 microM). Twenty-two LA positive plasma and 17 LA negative plasma from patients similarly enhanced the aggregation of platelets which were obtained from healthy adults and stimulated with low concentrations of ADP (1 or 2 microM). However, such enhancement of platelet aggregation was not observed when high concentrations of ADP (5 microM) or collagen (2 micrograms/ml) were used as stimulators. In four of the 16 LA positive plasma examined, the mixture of plasma and phospholipid reagent for activated partial thromboplastin time induced platelet aggregations without the other stimulations, but the plasmas themselves did not induce such a reaction. The above results indicate that the aPL from patients do not react with intact blood cells in vitro, but they can react with activated or destroyed blood cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies↗